Profile of cognitive impairment in dementia associated with Parkinson’s disease compared to Alzheimer disease
Abstract
Objective: To compare the profile of cognitive impairment in Alzheimer’s disease (AD) to dementia associated with Parkinson’s disease (PDD).
Methods: Neuropsychological assessment was performed in 488 patients with PDD and 488 patients with AD using MMSE and ADAS-cog. Logistic regression analysis was used to investigate whether the diagnosis could be accurately predicted from the cognitive profile. Additionally, the cognitive profiles were compared to a normative group using standardized effect-sizes (Cohen’s d).
Results: Diagnosis could be predicted from the cognitive profile with an overall accuracy of 74.7%. Poor performance of the AD patients on the orientation test in ADAS-cog best discriminated between the groups, followed by poor performance of the PDD patients on the attentional task in MMSE. Both groups showed memory-impairment, AD patients performing worse than the PDD patients.
Conclusion: The cognitive profile in PDD differs significantly from that in AD. Performance on tests of orientation and attention best differentiates the groups.







